Why does Internet Explorer in Windows Vista require a different Java level?
Internet Explorer running under Windows Vista runs with “protect mode” set to “on” by default. This mode restricts access to the filesystem by applets running under older Java levels. Java level 1.6.0_10 or above is required to gain filesystem access with protect mode on. You can also set “protect mode” to “off” to enable Download Director to work with any supported Java level.